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Mystery #2Tier 1-2earth & space / time

Why does a year last 365 days, and not some other number?

You get one birthday a year, every year, and it always comes round after the same long wait. Winter, then spring, then summer, then autumn, then back to the start. Something is patiently counting out 365 days each time. Why that number, and not 200 or 500?

The same large tree beside a farmhouse photographed four times: bare in winter, green in spring, full and leafy in summer, and golden in autumn.
Photo: Radler59 · CC BY-SA 3.0 · via Wikimedia Commons

Your guess

What do you think makes a year exactly as long as it is?

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